News: Urgent! Fix your SPF!

Published: 2022-03-02

Google appears to be stepping up their requirements for domains to be authenticated by SPF, DKIM, etc. We're seeing an increase in these errors from customers:

"421-4.7.0 This message does not have authentication information or fails to pass authentication checks. To best protect our users from spam, the message has been blocked. Please visit for more information."

Every time we see it, we find a customer who failed to follow our policy on SPF records. You are REQUIRED to allow us to send mail for your domain via your SPF record. The reason we require this should now be becoming obvious to you, because we don't like failed deliveries any more than you do. It makes you look bad; it makes us look bad, and by extension it risks making the rest of our customers look bad. PLEASE add our SPF record to your DNS if you do not already have it there!

Here are the technical details:

DNS Record Type: TXT
Record Contents: "v=spf1 -all"

If you want to hide MXroute in that, you can replace the include with any of these:

If your SPF looks similar to this:

"v=spf1 ip4: -all"

You've done it wrong. You were supposed to read the "Important Account Information" email entirely before you went loose in our system, it is vital to making up for some of our UX issues. You can find a copy here: